1. Field of the Invention
The present invention relates, in general, to biosensors, and, more particularly, to a vertical flow-type biosensor.
2. Description of the Related Art
The quantitative or qualitative analysis of analytic material present in a biological sample such as blood is important from a chemical or clinical standpoint. Representative examples thereof include the measurement of cholesterol which is the cause of various adult diseases and the measurement of blood sugar in blood for diabetics. As technology for measuring biological data such as cholesterol or blood sugar, methods of dropping a biological sample such as blood onto a measurement strip and detecting color change or electrochemical variation, which occurs as a result of enzymatic reaction in a reaction area, have been widely known.
In order to implement the above technology, technologies related to a measurement strip, that is, a biosensor, for measuring an analytic material contained in a biological sample have been proposed. For example, when blood sugar in blood is intended to be measured, a biosensor can measure the amount of blood sugar from extracted blood using an electrochemical method. However, the extraction of a biological sample including blood is an action that inflicts pain on the person whose biological sample is being extracted. As a result, in order to reduce pain, the amount of biological sample required for measurement needs to be minimized.
However, since the insufficiency of the amount of blood in a typical optical biosensor may greatly influence the results of analysis, it is important to load more than a predetermined amount of blood onto the measuring layer of the measurement strip. The volumes of red blood cells have a difference of 20 to 60% according to the human being. Accordingly, even if the same amount of blood is injected, there is the difference in the amount of blood serum which is separated from red blood cells and reaches a final reaction layer.